Sky News asked each of the UK's 45 territorial police forces for the number of illegal raves reported in the last three years.

History of illegal raves

Just 14 forces in England and Wales provided annual figures, meaning the actual number of illegal raves is likely to be much higher.

Overall, the number of reports of illegal raves rose to 682 in 2017, compared with 628 in 2016.

In London, the Metropolitan Police said there were 133 unlicensed music events in 2017 - nearly double the 70 recorded the previous year.

In one case this year, Jordan Gharib, 26, was jailed for 21 months for violent disorder after several police officers were injured at an illegal rave in Barking, east London, in June.

Image:Jordan Gharib was jailed for his part in an illegal rave that turned violent

Devon and Cornwall, South Yorkshire, Gwent, Cambridgeshire, West Midlands and Northamptonshire were among the other forces to record illegal raves in their areas.

Separately, Merseyside Police said it recorded 108 crime incidents related to raves, including complaints about noise and anti-social behaviour, between 2015 and April 2018.

Chief constable Ben-Julian Harrington, the NPCC's lead for sporting and planned events, told Sky News: "It is clear that unlicensed music events are a growing problem and they pose a real challenge to communities and police forces.

"Unlike licensed events, unlicensed music events are inherently unsafe. They lack safety provisions such as stewarding, security, fire regulation and medical support while regularly attracting a large number of people who cause damage and disturbance.

"Forces must balance the nuisance or damage caused with the overall safety of the local community, those attending and the police officers or other agencies who may need to respond."

DJ and student Stephane Massa, who regularly attends unlicensed music events in London, said he "hates being made to feel like a criminal".

"People may think that because there is no police or security that it goes wild but it really isn't like that," he told Sky News.

Image:Stephane Massa regularly attends unlicensed music events

"I think people are actually quite discreet and respectful. Most people genuinely don't have any intention to harm anyone or their surroundings.

"Obviously there are some people who push the boundaries - but that is the same in every nightclub in the country.

"A lot of the time the only problem is people not picking up litter after themselves."

The increase in illegal raves comes as the number of nightclubs in London fell by 8% between 2014 and 2017, according to figures from data firm CGA.

Meanwhile, the number of nightclubs across the rest of Britain - outside of the capital - dropped 6% from 2012 to 2017, CGA said.

Jeremy Abbott, digital editor at dance music magazine Mixmag, said the increasing popularity of illegal raves was a "worrying trend".

He said: "Clubs are more expensive than ever, the same goes for drinks prices in clubs. On the flip-side, it's worryingly easy to get your hands on drugs in London alone and the strength of ecstasy has sky-rocketed.

"It's an easy alternative to clubbing in the city and with many venues being shutdown it's a popular alternative.

"It's a worrying trend as of course these parties can't be properly policed or regulated so crime and risk of drug-related illness is higher."